The COG (Chip on Glass) packaging technology is to directly install a driving chip (generally (or) called as a driving IC, which usually has an integrated circuit therein) onto a lower glass substrate of a display, so that the required voltage or signal is output to a pixel of the display, and in turn, the degree of twisting of liquid crystal molecules or the pixel color is controlled. In the COG packaging technology, a plurality of output/input bumps are arranged on a surface of the driving chip, and the driving chip and metal traces on the lower glass substrate of the display are electrically connected by an anisotropic conductive film (ACF) or a non-conductive film (NCF).
As illustrated in FIG. 1, in prior art, a driving chip 1 is generally in a rectangular configuration, and a plurality of output/input bumps 2 are arranged at an edge of the driving chip 1 in columns, and connected to a lower glass substrate 4 by conductive corpuscles 3. It is a longer distance from an end of a bump column to an edge of the driving chip 1, and at either end of the driving chip 1, there is no bump for its support. During bonding, when the driving chip bears a greater pressure, it results in the fact that either end of the driving chip is deformed excessively, and there is a risk of overpressure in conductive corpuscles in an anisotropic conductive film on an output/input bump at either end of a bump column. After the pressure is removed, the driving chip will restore its shape, causing such an undesirable phenomenon that the impression at either end is shallower, and the impression in the middle is deeper. When the driving chip bears a smaller pressure, the deformation of either end of the driving chip is larger, the pressure acted upon conductive corpuscles in an anisotropic conductive film on an output/input bump at either end of a bump column is larger, and the impression is deeper; the pressure acted upon other part is smaller, and the impression is shallower. This causes such an undesirable phenomenon that the impression at either end is deeper, and the impression in the middle is shallower.